The present disclosure relates to a cover for an electronic device, an antenna assembly, an electronic device, and a method for manufacturing the same.
In general, antennas may be classified as external antennas installed outside of electronic devices and internal antennas installed inside of electronic devices. Interest in internal antennas has been increasing to provide various advantages in terms of ease in usage, a design, and the like.
With the advancement of communication technologies, portable terminals such as cellular phones have become multifunctional in order to provide functions such as a voice call, text communications, electronic payments, and the like, and antennas installed in portable terminals have also been diversified.
In addition, as development of portable terminals have moved towards high quality in terms of design, thicknesses of portable terminals have been increasingly reduced, while screens thereof have been increased in size. Thus, in order to reinforce strength thereof, metal is increasingly employed as a material for a cover (or a case, hereinafter generally referred to as a ‘cover’) forming an outer casing of electronic devices.
However, the employment of metal as a material for covers of portable terminals may negatively affect antenna performance in portable terminals and there may be negative aspects in that human bodies may be sensitive to electromagnetism from portable terminals formed of metal.
Thus, in the case of portable terminals, if antennas for main communications, as well for communications schemes such as a GPS, BT/Wi-Fi, or the like, are disposed on the upper and lower sides of portable terminals and the entirety of covers thereof are formed of metal, antenna performance may be degraded. In order to overcome the shortcomings, for example, a region of a cover in which an antenna is disposed may at least be formed of a material other than metal.
Also, in case of near field communications (NFC) antennas, increasingly employed in portable terminals, such NFC antennas may be disposed in an extra region, except for regions in which the antennas for main communication and for communications schemes such as GPS, BT/Wi-Fi, or the like, are disposed, as mentioned above. For example, the NFC antenna may be directly attached to a battery or attached to a battery cover. Namely, in consideration of arrangement areas of the other antennas, the NFC antenna may be disposed at the center of a rear surface of a portable terminal or in the vicinity of the center. In this case, however, such an arrangement of the NFC antenna may degrade performance when a metal cover is employed, which, thus, is a problem which remains to be solved.
As discussed above, there are limitations in forming the covers of existing portable terminals employing NFC antennas of metal, and thus, in some cases, upper and lower sides in which antennas for main communications and for communication schemes such as GPS, BT/Wi-Fi, or the like, are arranged are formed of a non-metallic material such as plastic.
However, the formation of a single cover of a portable terminal with different materials such as metal and a non-metallic material may result in a complicated process in terms of manufacturing and may be disadvantageous in terms of time and cost.
In addition, in a case in which an NFC camera is employed in a portable terminal including a metal cover, if an NFC antenna pattern coil is disposed on an inner surface of the metal cover, a repulsive magnetic field may be generated according to Lenz's law, resulting in the formation of an eddy current in a direction opposite a direction of a current flowing in the antenna pattern coil so as to interfere with current flow of the antenna pattern coil. This degrades performance of the NFC antenna.
In order to address this problem, in an existing portable terminal, there has been an attempt to form a physical slit such that a hole formed in a cover of a portable terminal communicates with an end portion of the edge of the cover formed of metal to reduce the generation of eddy currents to thus enhance antenna performance.
However, the formation of a slit in the metal cover may mar an aesthetic appearance of such a metal case. Thus, in order to prevent the slit from being exposed, an additional member needs to be attached and a surface thereof needs to be painted. Namely, additional operations need to be inevitably performed.
Meanwhile, as metal has been increasingly employed as a material of a cover of electronic devices such as smartphones as mentioned above, a need exists for a metal cover for an electronic devices used as an antenna.